1. Field of the Invention
The present invention relates to systems of electromagnetic or electromechanical stimulation of acoustic musical instruments for the purpose of high fidelity production or reproduction of music.
2. Background Art
Acoustic instruments (i.e., non-electrical instruments) are the instruments of choice for performing most musical pieces. Acoustic instruments typically excite a moveable element near an air chamber to produce sounds. For example, in a violin, guitar or piano, strings are manipulated, excited and amplified by a sound chamber to produce sound; in a clarinet, oboe or saxophone, a reed is excited like a valve, and regulates a moving column of air down the bore of the instrument to produce sounds; in drums, a tightly-stretched membrane is excited and amplified by the drum body to produce sounds.
In the creation of recorded music, it is often desired to utilize acoustic instruments as part of the recorded performance. However, this often limits the repeatability of performances for recording and limits the venues where recording sessions can take place. For example, since acoustic instruments are recorded through the air, the acoustics of the recording locations are critical. This often prevents the use of a live acoustic performer when the recording is to be done at a small studio or a home environment. Further, if a large number of acoustic instruments are desired, the expense and logistics of supporting a large number of live performers is typically prohibitive. One prior art attempt to solve the problem of providing acoustic sounds for recording purposes is to substitute electronically-produced sounds such as from a synthesizer, sampler or the like. Mile such efforts can provide solutions to the problem of repeatability of performance, venues of recording sessions and expense, these prior art attempts do not provide satisfactory solutions to the problems of sound fidelity and authenticity. Synthesizers do not recreate strings or other acoustic instruments effectively, sounding artificial and lacking the richness and variety of live performers. High fidelity sampling techniques are expensive in terms of dollars and memory requirements, and also fall short of the real thing in terms of flexibility and acoustic authenticity.
There are methods in existence between the extremes of reproduction and live performance. The player piano, for example, is a device which can reproduce music on a real piano without the need for a human pianist. The player piano affords a composer with the convenience of storage and playback capability. Obviously though, the sounds producible by a piano cannot encompass other instruments such as strings or winds. Prior art player pianos are described in U.S. Pat. Nos. 4,843,936; 4,756,223; 4,744,281; 4,593,592; 4,469,000; 4,417,494 and 4,383,464.
Attempts have been made to record and reproduce a player piano musical performance synchronized with an orchestral recording. This complex mechanical reproduction, while a faithful reproduction of a piano, makes no attempt to faithfully reproduce other instrument groups, relying on the traditional loudspeaker for that purpose.
Presently, music is performed either acoustically or electronically or in combination, recorded through an electronic mixing board onto digital or sound tape and replayed electromagnetically through fiber speaker cones. Rarely, music is performed on a player piano, performance data being stored digitally, then replayed by a player piano mechanically reproducing the piano's real sound. In the case of electronic recordings, fidelity is lost during each step of the process. Even during the initial performance of the acoustic instruments, noise and distortion are introduced. Using the player piano method, an acoustic performance is reproduced mechanically with hammers and pedals, but only a piano is reproduced, mechanical delay is introduced and flexibility is lacking.
A preferred source material to drive a violin string is the "sample." A sample is generally the recording of a single musical note. This sample is a detailed "photographic" description of note attack, timbre, harmonic structure, sustain, volume and decay. A sample is a more complex structure, and contains more information, than waveforms typically generated by a synthesizer. When amplified and played back through a loudspeaker, a sample is indistinguishable from an original musical performance played through the same loudspeaker.
Samples are typically recorded one at a time, by slowly playing a scale of individual notes. The individual notes can subsequently be linked together in any desired order to create a new performance. One advantage of this method is that any sample can follow any other sample, creating an extremely flexible composition or performance environment tool.
However, there are a number of disadvantages to the single sample method. First, a single sample always starts with an attack, a crucial element of a musical sample. This attack may be adequate for some musical passages, such as those requiring individual attacks for each note. For other passages, such as legato or finger section, the single sample attack is inadequate. Second, the identifying "signature" of the single sample attack is always the same whenever that particular sample is played. This phenomenon is especially obvious when a specific sample is repeated. This sameness of attack is literally never found in the real world of acoustic instruments, where each attack is unique and different, always changing slightly, due to the human input. Third, because of the nature of current sampling technology, loops (the repeating of a sample section) are required. This looping can make a performance created from samples sound mechanical and artificial, because of the repetitive nature of the looping. In an actual performance, the same sound is rarely repeated.